Treatment liquid and method for treating object to be treated

1. A treatment liquid comprising: water; hydroxylamine; and three kinds of first anions consisting of Cl−, NO2−, and NO3−, wherein a total content of the first anions is 0.0001 to 30 parts by mass with respect to 100 parts by mass of the hydroxylamine.

2. The treatment liquid according to claim 1, further comprising: one or more kinds of second anions selected from the group consisting of SO42− and PO43−, wherein a total content of the first anions and the second anions is 0.0001 to 30 parts by mass with respect to 100 parts by mass of the hydroxylamine.

3. The treatment liquid according to claim 1, wherein a total mass of the contained two kinds of specific anions consisting of NO2− and NO3− is larger than a mass of the contained Cl−.

4. The treatment liquid according to claim 1, further comprising: a chelating agent.

5. The treatment liquid according to claim 4, wherein the chelating agent contains a functional group selected from the group consisting of a carboxylic acid group, a phosphonic acid group, and a sulfonic acid group.

6. The treatment liquid according to claim 4, wherein the chelating agent is one or more kinds of compounds selected from the group consisting of diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, trans-1,2-diaminocyclohexanetetraacetic acid, oxalic acid, malonic acid, succinic acid, citric acid, methanesulfonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, and nitrilotrismethylenephosphonic acid.

7. The treatment liquid according to claim 1, further comprising: an anticorrosive.

8. The treatment liquid according to claim 7, wherein the anticorrosive is benzotriazoles.

9. The treatment liquid according to claim 8, wherein the benzotriazoles are benzotriazole that may be substituted with one or more kinds of substituents selected from the group consisting of an alkyl group which may further contain a substituent, an aryl group which may further contain a substituent, a halogen atom, an amino group which may further contain a substituent, a nitro group, an alkoxy group which may further contain a substituent, and a hydroxyl group.

10. The treatment liquid according to claim 7, wherein the anticorrosive is one or more kinds of compounds selected from the group consisting of benzotriazole, 5-aminotetrazole, 1-hydroxybenzotriazole, 5-phenylthiol-benzotriazole, 5-chlorobenzotriazole, 4-chlorobenzotriazole, 5-bromobenzotriazole, 4-bromobenzotriazole, 5-fluorobenzotriazole, 4-fluorobenzotriazole, naphthotriazole, tolyltriazole, 5-phenyl-benzotriazole, 5-nitrobenzotriazole, 4-nitrobenzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole, 1-amino-benzotriazole, 5-methyl-1H-benzotriazole, benzotriazole-5-carboxylic acid, 4-methylbenzotriazole, 4-ethylbenzotriazole, 5-ethylbenzotriazole, 4-propylbenzotriazole, 5-propylbenzotriazole, 4-isopropylbenzotriazole, 5-isopropylbenzotriazole, 4-n-butylbenzotriazole, 5-n-butylbenzotriazole, 4-isobutylbenzotriazole, 5-isobutylbenzotriazole, 4-pentylbenzotriazole, 5-pentylbenzotriazole, 4-hexylbenzotriazole, 5-hexylbenzotriazole, 5-methoxybenzotriazole, 5-hydroxybenzotriazole, dihydroxypropylbenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]-benzotriazole, 5-t-butylbenzotriazole, 5-(1′,1′-dimethylpropyl)-benzotriazole, 5-(1′,1′,3′-trimethylbutyl)benzotriazole, 5-n-octylbenzotriazole, and 5-(1′,1′,3′,3′-tetramethylbutyl)benzotriazole.

11. The treatment liquid according to claim 1, further comprising: one or more kinds of organic solvents selected from the group consisting of an alcohol-based solvent, a ketone-based solvent, an ester-based solvent, and an ether-based solvent.

12. The treatment liquid according to claim 1, which has a pH of 6 to 11.

13. The treatment liquid according to claim 1, which is used for an object to be treated that contains a cobalt-containing substance containing cobalt atoms and a metal-containing substance containing metal atoms other than cobalt atoms.

14. The treatment liquid according to claim 13, wherein the cobalt-containing substance is simple cobalt, a cobalt alloy, a cobalt oxide, or a cobalt nitride.

15. A method for treating an object to be treated, comprising: bringing an object to be treated that contains a cobalt-containing substance containing cobalt atoms into contact with the treatment liquid according to claim 1 so that the cobalt-containing substance is dissolved.

16. A method for treating an object to be treated, comprising: a step A of performing a treatment on an object to be treated containing a metal layer so that a surface layer of the metal layer is oxidized and turns into a metal oxide layer; and a step B of bringing the object to be treated obtained by the step A into contact with the treatment liquid according to claim 1 so that the metal oxide layer is dissolved, wherein the treatment in the step A is a liquid treatment of bringing the object to be treated into contact with a solution selected from the group consisting of water, hydrogen peroxide water, a mixed aqueous solution of ammonia and hydrogen peroxide, a mixed aqueous solution of hydrofluoric acid and hydrogen peroxide water, a mixed aqueous solution of sulfuric acid and hydrogen peroxide water, a mixed aqueous solution of hydrochloric acid and hydrogen peroxide water, water containing dissolved oxygen, and water containing dissolved ozone, an ozone treatment of bringing the object to be treated into contact with an ozone gas, a heating treatment in oxygen in which the object to be treated is heated in an oxygen atmosphere, and a plasma treatment using an oxygen gas.

17. The method for treating an object to be treated according to claim 16, wherein the step A and the step B are alternately repeated.

18. The method for treating an object to be treated according to claim 16, wherein the metal layer is simple cobalt or a cobalt alloy.

19. A method for treating an object to be treated, comprising: performing a dry etching treatment on an object to be treated containing a metal-based material; and then bringing the object to be treated into contact with the treatment liquid according to claim 1 so that dry etching residues are removed.

20. The method for treating an object to be treated according to claim 19, wherein the metal-based material is a cobalt-containing substance containing cobalt atoms.